Semiconductor devices are used in a variety of electronic applications, such as personal computers, cell phones, digital cameras, and other electronic equipment, as examples. The semiconductor industry continues to improve the integration density of various electronic components (e.g., transistors, diodes, resistors, capacitors, etc.) by continual reductions in minimum feature size, which allow more components to be integrated into a given area. These smaller electronic components also require smaller packages that utilize less area than packages of the past, in some applications. One type of smaller packaging that has been developed is three-dimensional (3D) ICs, in which two die or ICs are bonded together and electrical connections are formed between the die and contact pads on an interposer.
Typically, power and ground lines are routed to logic gates and other devices in integrated circuits. The current from a power supply flows through the power lines, logic gates, and finally to ground. During the switching of the logic gates, a large amount of change in the current may occur within a short period of time. Decoupling capacitors are used to absorb these glitches during current switching. Decoupling capacitors function as charge reservoirs by maintaining a constant voltage between the supply voltage and ground, preventing momentary drops in the supplied voltage.